Safe Omission of Postoperative Neck Irradiation in Selected pN0 Patients With Locally Advanced Oral Cavity Squamous Cell Carcinoma

BACKGROUND: Postoperative radiotherapy is the standard treatment for locally advanced oral squamous cell carcinoma (OSCC); however, the indication for neck irradiation (NI) in pN0 patients remains debatable. We evaluated whether the omission of NI compromises outcomes in pT3-T4 pN0 patients treated with adequate neck dissection (ND). METHODS: This retrospective single-institution study included patients with pT3-T4pN0 OSCC who underwent primary surgery, exhaustive ND (≥ 18 lymph nodes), and postoperative radiotherapy limited to the tumor bed. Overall survival (OS), disease-free survival (DFS), and regional control were also analyzed. RESULTS: Seventy-seven patients were included in the study. After a median follow-up of 51 months, only three nodal recurrences occurred, all associated with local tumor relapse. No isolated neck failures were observed. The regional control rate was 96% and the 5-year OS and DFS rates were 77.6% and 79.2%, respectively. CONCLUSION: In selected pT3-T4 pN0 OSCC patients undergoing high-quality ND, omission of postoperative NI does not compromise oncologic outcomes. This strategy allows for a meaningful reduction in irradiation volumes and potentially treatment-related morbidity, supporting de-escalation of treatment.